Canon 1dx or Canon 5dmark111

[I @ M]

Ken Rockwell has a bit of a comparison here (I hope it's ok to post the link?).

Yep, perfectly OK to post the link to Mr. Rockwell, we like a bit of humour here and he is a first class provider of it in his attempt to enlighten the photographic community with his pearls of wisdom make money from gullible people.

I haven't been lucky enough to even hold either of these two cameras and know very little about them

In all seriousness, I reckon Mr Rockwelll is in exactly the same boat as you.